Topographically organized dorsal raphe activity modulates forebrain sensory-motor representations and contributes to defensive behaviors - Nature Communications

Functional heterogeneity of dorsal raphe nucleus is not fully understood. Here authors show topographically organized sensory and locomotor responses from the zebrafish dorsal raphe and its forebrain ...

nature.com

Distinct neurogenic pathways shape the diversification and mosaic organization of cortical output channels

The cerebral cortex broadcasts its output to subcortical regions through the projections of diverse extratelencephalic (ET) neurons derived from eithe…

sciencedirect.com

Species-specific chromatin architecture and neurogenesis mediated by a human enhancer

How human-specific DNA changes shape brain development is poorly understood. Mosti et al. discover a human enhancer, HAR1984, which drives ETV5 and TRA2B expression via human-enriched chromatin intera...

cell.com

A synaptic locus of song learning

Learning by imitation is the foundation for verbal and musical expression, but its underlying neural basis remains obscure. A juvenile male zebra finch imitates the multisyllabic song of an adult tutor in a process that depends on a song-specialized cortico-basal ganglia circuit, affording a powerful system to identify the synaptic substrates of imitative motor learning. Plasticity at a particular set of cortico-basal ganglia synapses is hypothesized to drive rapid learning-related changes in song before these changes are subsequently consolidated in downstream circuits. Nevertheless, this hypothesis is untested and the synaptic locus where learning initially occurs is unknown. By combining a computational framework to quantify song learning with synapse-specific optogenetic and chemogenetic manipulations within and directly downstream of the cortico-basal ganglia circuit, we identified the specific cortico-basal ganglia synapses that drive the acquisition and expression of rapid vocal changes during juvenile song learning and characterized the hours-long timescale over which these changes consolidate. Furthermore, transiently augmenting postsynaptic activity in the basal ganglia briefly accelerates learning rates and persistently alters song, demonstrating a direct link between basal ganglia activity and rapid learning. These results localize the specific cortico-basal ganglia synapses that enable a juvenile songbird to learn to sing and reveal the circuit logic and behavioral timescales of this imitative learning paradigm. ### Competing Interest Statement The authors have declared no competing interest. National Institutes of Health, K99 NS144525 (DCS), F32 MH132152 (DCS), F31 HD098772 (SB), R01 NS099288 (RM), RF1 NS118424 (RM and JP)

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